Vitamins support normal growth, development, and cell functions. All B vitamins help convert carbohydrates into a source of energy (glucose), and assist in the formation of red blood cells.
It is thought that B vitamins may affect depression in these ways:
There is very little scientific evidence on vitamin B6 and B12 for the treatment of depression. More studies of better quality are needed.
Short-term use of vitamins by themselves do not seem to help reduce depression symptoms. Some studies have found that taking folate (B9) alongside anti-depressant medication can be helpful, and one study found that long-term use of B vitamins reduced the risk of relapse for people who had recovered from depression.
Some vitamin supplements can be harmful or ineffective if you take the wrong dose. For example, large doses of Vitamin B6 can cause nerve damage. Talk to your health care professional if you are thinking of taking supplements.
One study reported mania symptoms in a participant who was taking folate (B9) (and antidepressants). No other studies of B vitamins and depression have reported side effects. However, it is not clear whether the studies have investigated negative effects. More research is needed on the possible side effects of B vitamins.
Vitamins are present naturally in food. You can buy vitamin supplements in health food shops, supermarkets or from chemists. They usually come in tablet, capsule or powder form. Vitamins may also be given as an injection by a doctor.
Vitamins as a standalone treatment do not appear to be effective at treating depression. Folate (B9) may help boost the effects of anti-depressants.
Last reviewed and updated: 1 May 2019